Selecting device for automatic or semi-automatic telephone systems.



G. A. BETULANDER & N. G. I'ALMOHLN. SELECTING DEVICE FOR AUTOMATIC 0R SEMI-AUTOIMTIC THE-PHONE SYSTEMS.

APPLICATIONFILED JUNE 26.1914.

w Patented Nov, 21, 1916.

m slim- W Z5 GOTTHILF ANSGARIUS BETULANDER, 0F SODERTORNS VILLASTAD, AND NILS GUNNAR 1 PALMGEEN, OF STOCKHOLM, SWEDEN, ASSIGNORS TO THE BETULANDER AUTO- MATIC TELEPHONE COMPANY LIMITED, OF LONDON, ENGLAND.

SELECTING DEVICE FOR AUTOMATIC OR SEMI-AUTOMATIC TELEPHONE SYSTEMS.

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Specification of Letters Iatent. Patagnted N 21 1916;

Application filed June 26, 1914. Serial-No. 847,495.

To all whom it may concern Be it known that we, GOTTHILF ANSGARIUS BETULANDER, a subject of the King of Sweden, and resident of Villa Castor, Sodertorns Villastad, in the Kingdom of Sweden, and NILS GUNNAR PALMcnEN, a subject of the King of Sweden, and resident of 35 Tjarhofsgatan, Stockholm, in the Kingdom of Sweden, have invented certain new and useful Improvements in Selecting Devices for Automatic or Semi-Automatic Telephone Systems, of which the following is a specification, reference being had therein to the accompanying drawings. 7

The invention relates to line selecting devices for automatic or semi-automatic telephone systems and more specially to selecting devices which consist of relays, and the selecting relays of which are affected in correspondence with the engaged or disengaged condition of the appertaining line.

The object of the invention is to simplify selecting devices of that class. This is attained according to the invention by only one selecting relay being assigned to each selecting stage, the operating circuits of the selecting relays being controlled by a common relay adapted to prevent the affecting of the selecting device by the selected line being marked as engaged.

The figure shows one form of the invention as applied to a telephone system in which the connections are effected by means of relays.

In the example shown'in the drawing a talking vline 1 is adapted to be connected with any of a number of lines 2, 3 and 4 by means of relays 5, 6 and 7 and contacts 8, 9 and 10 respectively. The selection of a disengaged line 2, 3 or 1 is effected by means of a selecting device consisting of a series of selecting or testing relays 11, 12 and 13 one selecting relay being provided for each line 2,3 and 4. The operation of the selecting device is controlled by a set of common relays 14, 15 and 16. Each selecting relay has two windings viz. a test winding 17, connected with the test wire 18 of the corresponding line 2, 3 or 41, and a locking winding 19. A line 2, 3 or 4: is marked as engaged by earth being connected to the test wire 18 through a contact 20 of a connecting relay 5, 6 or 7.

Although only one line 1 is shown, yet it locked over its contact 30.

is supposed that the lines 2, 3 and 4 are common to a plurality of lines 1.

When the line 1 is to be connected with one of the lines 2, 3 or 4, a contact 21 is first closed. This causes a flow of current from the earthed pole of a battery22 through relay 14, contact 23 of a relay 21, assigned to the line 1, and contact 21 to the negative pole of the battery. The relay 14, upon energizing, closes the contact 25 thereby effecting the energization of those of the selectlng relays, corresponding to engaged llnes 2, 3 or 4, over circuits including contact 20, Wire 18, winding 17, contact 26 of In this instance it fore opens the operating circuits of all selecting relays at the contact 26. The connection with the first disengaged line 3 is now established through the mediation of the relay 24 which is energized through contact 28, contact 29 and contact 21 and is A circuit is thereby closed extending from earth through contact 28 of relay 15, contact 31 of relay 11, contact 32 of relay12, wire 33, relay 6, contact 34 of relay 24 and contact 21 to the battery. The connecting relay 6 energizes upon the closure of that circuit and is locked over its contacts 35 and 20. The line 1 is thereby connected with the line 3 through contact 9 of relay 6 and the connection is then maintained as long as the contact 21 is closed. Although the test wire 18 of the line 3 is connected to earth in the moment of establishing the connection, yet the corresponding selecting relay 12 is not thereby affected as the operating circuits of the selecting relays are open at contact 26 of relay 16. The relay 16, therefore, prevents disturbances which else might be caused by the selected line being marked as engaged in the connecting moment. Disturbances which might occur on account of a line being disengaged in the connecting moment, are prevented by the selecting relays being locked over circuits (27, 25, 22 independent of the engaged and disengaged condition of the lines'2, 3 and 4.

At the opening of contact '23 the relays 14, 15 and 16 are deenergizedsuccessively the selecting device being thereby restored into normal condition. The connection between lines 1 and 3 is severed by opening the con-.

tact 21 the relays 6 and-'2lbeing thereby o de'c'nergized.

The selecting device is shown as allotted to only one line 1 but it may also be used 1. Anon-numerical selecting device consisting'of relays and comprising one selecting relay for each selective position, operating circuits "for .saidv relays-including means for'marking the selective lines as engaged, and a common relay controllingthe operating circuits of saidrela'ys so as to prevent re-operation of the selecting device by a selected line being marked as engaged.

' 2. A non-numerical selecting device consisting of relays and comprising one select- 1 ing relay for each selective position, operating circuits for said relays including means for marking the selective lines as engaged, holding circuits for said relays independent of the condition of the selectable lines, and a common relay controlling I the operating circuits of said relays so as to prevent re-operation of the selecting device by a selected line be ng marked as en- .gaged.

In Witness whereof, we have hereunto signed our names in thepresence of two subscribing witnesses.

GOTTHILF ANSGARIUS BETULANDERV NILS GUNNAR PALMGREN.

Witnesses: y

J. ST. VI CENT PLErrs,

FREDK. A'rKIN. 

